12 Charlotte potatoes, peeled
200g/7oz datterini or cherry tomatoes, cut in half
1 large fennel bulb
squeeze lemon juice
2 tbsp chopped parsley
1 tbsp capers in vinegar, drained
2 heaped tbsp pitted black olives, preferably taggiasca
sea salt and freshly ground black pepper
2 tbsp extra virgin olive oil, plus extra for drizzling
extra virgin olive oil, to serve
2 whole red mullets, scaled and filleted